Various films such as conductive metals, refractory metals and other materials such as semiconductor materials, are deposited using deposition equipment that involves physical vapor deposition, PVD, also known as sputtering. Included among the films deposited using this method are various metals such as aluminum copper, AICu, aluminum silicon, Alsip, aluminum silicon copper, AISiCu, aluminum, Al, copper, Cu, and other conductive films. Refractory films such as tungsten, W, tungsten silicide, Wl, tantalum, Ta, titanium, Ti, titanium nitride, TiN, tantalum nitride and various other films represent just a sample of the many different films used in semiconductor manufacturing and formed using physical deposition methods. The thicknesses of the films deposited using these methods vary in various devices. Some devices such as cell phone devices require very thick metal films such as metal films having thicknesses in the range of about 500,000 angstroms.
The amount of film deposited varies with deposition time for a given power and given deposition rate. As such, thicker film requires a longer deposition time and therefore power is applied for a longer duration. Also a higher power produces a thicker film for a fixed deposition duration. The application of power and the PVD deposition operation itself, including the plasma in the PVD operation, causes the sputtering target and the entire chamber to heat up. The temperature is raised for all components within the chamber, including the substrate, e.g. wafer, upon which the film is being deposited. The temperature of the substrate increases with increased process time and increased power.
Included in the deposition chamber is a heater often used to heat the substrate during deposition to a processing temperature.
When the substrate temperature is high due to the heater and/or the power and resulting plasma used in a deposition process, the substrate is prone to stick to other components in the chamber, and this is especially true when a thick film is being deposited upon the substrate surface.
When the deposition operation is concluded, the heater needs to be cooled to cool the substrate and in order to remove the substrate from the chamber. If the heater cannot be efficiently cooled when the processing is concluded, the substrate sticks on the chuck and its removal can cause deformation or breakage of the substrate.
In order to avoid this sticking phenomenon, films having a thickness greater than a threshold thickness, are deposited in multiple steps, i.e. multiple separate processing operations. The multiple process operations are commonly carried out in different processing chambers.
It would be desirable to deposit films to any desired thickness in one operation and to cool the components efficiently and quickly upon conclusion of the deposition process.